The \ ensures that $2 is not interpreted until the alias is use. Note that it only looks for the username in the first field (indicated by the ^ to mark the beginning of the lines and displays the second field. To see just the process IDs, you could set up an alias like this one: $ alias myps=”ps aux | grep ^`whoami` | awk ''” bashrc file to, the alias will be ready to use. bashrc file with a line like this: $ echo 'alias myprocs="ps -ef | grep `whoami`"' > ~/.bashrc For example, the command shown below that lists all processes associated with the current login account could be added to the user’s. In fact, pipes are so useful that I often turn some of the commands that incorporate them into aliases to make running them even that much easier. You might see them referred to as “unnamed pipes” or “anonymous pipes” because they are not the only kind of pipes that Linux provides. The command above would send the content of a file called “myposts” to a grep command looking for the word “Linux” and then send that output to a wc command to count the number of lines in the output.Īs you probably suspect, pipes are called “pipes” largely because of how they resemble the function of pipelines. Commands incorporating pipes – like the one shown below – allowed me to extract just the information that I needed without having to compile a program or prepare a script. Using pipes, I discovered how much I could get done by sending the output of one command to another command, and sometimes a command after that, to further tailor the output that I was looking for. My appreciation of their power and convenience continues even after decades of using Linux. In fact, pipes were one of the things that really got me excited when I first used the command line on a Unix system. So, don’t hesitate to open your terminal and start typing away!įor more information on Linux commands, you can refer to the Linux Command Line Guide.Most people who spend time on the Linux command line move quickly into using pipes. Remember, practice is key when it comes to mastering Linux commands. Understanding this command and how to use it effectively can greatly enhance your Linux system administration skills. It combines the power of ps, grep, and the pipe symbol to provide a detailed overview of specific processes. In conclusion, the ps -ef | grep processname command is an essential tool for managing and monitoring processes in Linux. For example, if you want to check if a service like Apache is running, you can use the command ps -ef | grep apache. This command is particularly useful when you’re dealing with a large number of processes and need to find a specific one quickly. This output is then passed to the grep command, which searches for and displays lines containing the processname. So, when you run ps -ef | grep processname, the ps -ef command generates a detailed list of all processes. When you replace processname with the actual name of the process, grep will filter out all lines that contain that process name. The processname is the name of the process you’re looking for. In the context of ps -ef | grep processname, grep is used to search the output of ps -ef for a specific process name. Grep is a command-line utility used to search text or output based on specified patterns. In this case, it sends the output of the ps -ef command to the grep command. It is used to redirect the output of one command to the input of another. The pipe symbol | is a key component of this command. This includes additional details such as the UID, PID, PPID, C, STIME, TTY, TIME, and CMD. The -f option instructs ps to display full format listing. The -e option tells ps to display all processes, not just those associated with the current user. The -ef option is used in conjunction with the ps command. It provides information such as the process ID (PID), the time the process has been running, the command that started the process, and more. The ps command is used in Linux to list the currently running processes.
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